Re: [PATCH] driver core: platform: Rename platform_get_irq_optional() to platform_get_irq_silent()

[Uwe Kleine-König]

On Thu, Jan 13, 2022 at 11:57:43PM +0300, Sergey Shtylyov wrote:
> On 1/13/22 11:17 PM, Mark Brown wrote:
> 
> >> The subsystems regulator, clk and gpio have the concept of a dummy
> >> resource. For regulator, clk and gpio there is a semantic difference
> >> between the regular _get() function and the _get_optional() variant.
> >> (One might return the dummy resource, the other won't. Unfortunately
> >> which one implements which isn't the same for these three.) The
> >> difference between platform_get_irq() and platform_get_irq_optional() is
> >> only that the former might emit an error message and the later won't.
> 
>    This is only a current difference but I'm still going to return 0 ISO
> -ENXIO from latform_get_irq_optional(), no way I'd leave that -ENXIO there
> alone... :-)

This would address a bit of the critic in my commit log. But as 0 isn't
a dummy value like the dummy values that exist for clk, gpiod and
regulator I still think that the naming is a bad idea because it's not
in the spirit of the other *_get_optional functions.

Seeing you say that -ENXIO is a bad return value for
platform_get_irq_optional() and 0 should be used instead, I wonder why
not changing platform_get_irq() to return 0 instead of -ENXIO, too.
This question is for now only about a sensible semantic. That actually
changing platform_get_irq() is probably harder than changing
platform_get_irq_optional() is a different story.

If only platform_get_irq_optional() is changed and given that the
callers have to do something like:

	if (this_irq_exists()):
		... (e.g. request_irq)
	else:
		... (e.g. setup polling)

I really think it's a bad idea that this_irq_exists() has to be
different for platform_get_irq() vs. platform_get_irq_optional().

> > Reviewed-by: Mark Brown <broonie@xxxxxxxxxx>
> 
>    Hm... I'm seeing a tag bit not seeing the patch itself...

See https://lore.kernel.org/all/20220113194358.xnnbhsoyetihterb@xxxxxxxxxxxxxx/

This is just a tree-wide
s/platform_get_irq_optional/platform_get_irq_silent/ + a macro to not
break callers of platform_get_irq_optional().

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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